If you one of the millions of Americans who happen to hold traditional, Conservative beliefs, you might want to consider skipping your next trip to the UK.

Canadian right-wing journalist and activist Lauren Southern says she was detained in the French port town of Calais Sunday night by UK authorities under the Schedule 7 anti-terrorism act, which allows law enforcement to stop, search and interrogate those under “reasonable suspicion” of being involved in terrorism. Accusing her of the “distribution of racist material,” British immigration authorities ultimately banned her from entering the country.

Southern made the claim via a series of tweets on Monday morning. The activist says she was on a bus traveling to the England Sunday night in order to appear at a free speech event. Border police, however, stopped her from entering the country, citing “racism” as their rationale for blocking her entry into the country:

Investigated me under schedule 7 (terrorism act) because of alleged racism. At least they let me identify as Pakistani on my report lol. Still being held by police. pic.twitter.com/LhZFK2d8Jh

Thank you all so much for the love and support as well. Just seeing how insane my notifications are. There's so much passion for free speech despite our bureaucrats best efforts to squash it. Don't let that flame die ❤️????

Reporter Chris Tomlinson, who has been tracking the story, provided a few more details:

Another message from @Lauren_Southern . She's being held in Calais, asked about her relationship to @BrittPettibone and a recent speech she gave for @vbjongeren the youth movement of @vlbelang . Now her phone has been taken away. No word on when she will be released.

Among the reasons she was detained is “distribution of racist material in Luton.” Here’s a copy of the letter to Southern from British authorities concluding that she presents a “threat to the fundamental interests of society and to the public policy of the United Kingdom”:

Southern was traveling to the UK after producing a documentary about racial tensions in South Africa reaching a “boiling point,” escalated by a government that has increasingly embraced racially discriminatory policies, including the confiscation of white-owned farmland. Southern posted the trailer for the documentary soon after she was released by authorities:

Southern’s banning follows a similar situation with Austrian right-wing “Identitarian” activist Martin Sellner and journalist, Brittany Pettibone, who were both detained a few days before at London Heathrow and ultimately blocked from entering the country for similar charges. Southern recently sat down with Pettibone for an interview on her South Africa documentary, in which she presents her rationale for undertaking the project.

The BBC provides some more details on the UK’s controversial Schedule 7 anti-terrorism law (formatting adjusted):

Under the schedule, UK police can stop, examine and search passengers at ports, airports and international rail terminals. Unlike with some other police powers to stop and search, there is no requirement for an officer to have a “reasonable suspicion” that someone is involved with terrorism before they are stopped.

A passenger can be held for questioning for up to nine hours and those detained must “give the examining officer any information in his possession which the officer requests”. Any property seized must be returned after seven days, but data from mobile phones and laptops may be downloaded and retained by the police for longer.

Those detained are compelled to answer questions from the police and must not “obstruct” or “frustrate” any police searches. If someone fails to co-operate they are deemed to have committed a criminal offence and could face up to three months in prison, a fine or both.